// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef NET_DNS_NOTIFY_WATCHER_MAC_H_
#define NET_DNS_NOTIFY_WATCHER_MAC_H_

#include "base/callback.h"
#include "base/macros.h"
#include "base/message_loop/message_loop.h"

namespace net {

// Watches for notifications from Libnotify and delivers them to a Callback.
// After failure the watch is cancelled and will have to be restarted.
class NotifyWatcherMac : public base::MessageLoopForIO::Watcher {
public:
    // Called on received notification with true on success and false on error.
    typedef base::Callback<void(bool succeeded)> CallbackType;

    NotifyWatcherMac();

    // When deleted, automatically cancels.
    ~NotifyWatcherMac() override;

    // Registers for notifications for |key|. Returns true if succeeds. If so,
    // will deliver asynchronous notifications and errors to |callback|.
    bool Watch(const char* key, const CallbackType& callback);

    // Cancels the watch.
    void Cancel();

private:
    // MessageLoopForIO::Watcher:
    void OnFileCanReadWithoutBlocking(int fd) override;
    void OnFileCanWriteWithoutBlocking(int fd) override { }

    int notify_fd_;
    int notify_token_;
    CallbackType callback_;
    base::MessageLoopForIO::FileDescriptorWatcher watcher_;

    DISALLOW_COPY_AND_ASSIGN(NotifyWatcherMac);
};

} // namespace net

#endif // NET_DNS_NOTIFY_WATCHER_MAC_H_
